How are the Teeth Numbered
Dentists and orthodontists use dental notation systems to identify and record information about specific teeth. There are three primary system that are used to do this; FDI World Dental Federation notation, Universal numbering system, and Palmer notation method. The FDI World Dental Federation Notation is used internationally, whereas the Universal numbering system is mostly used by general dentists in the United States and the Palmer Notation Method is used predominantly by dental students and dentists in the United Kingdom.
FDI World Dental Federation Notation
The FDI World Dental Federation notation is used internationally in many countries. This system was developed by the Fédération Dentaire Internationale. The system uses a two digit numbering system that identifies the quadrant the tooth is in and its position in the jaw. The numbers given to the teeth depend on whether the teeth are the deciduous (baby) teeth or the permanent (adult) teeth.
The FDI World Dental Federation notation divides the mouth into four quadrants from the midline of the face. When counting the deciduous teeth, the upper right quadrant of the mouth begins with the number 5, the upper left with the number 6, the lower left with the number 7 and the lower right with the number 8. The teeth are then counted from the midline to the back of the jaw starting at one. So the top front right tooth is 51, the top front left tooth is 61, the front left bottom tooth is 71 and the front right bottom tooth is 81.
When counting the permanent (adult) teeth, the upper right quadrant of the mouth begins with the number 1, the upper left with the number 2, and the lower left with the number 3 and the lower right with the number 4. The teeth are then counted from the midline to the back of the jaw starting at one. So the top front right tooth is 11, the top front left tooth is 21, the front left bottom tooth is 31 and the front right bottom tooth is 41.
Universal numbering system
The Universal Numbering System is used predominantly in the United States. The notation used for the deciduous teeth is different than that used for the permanent teeth. The deciduous teeth are referred to using the capital letters from A to T. In this system to teeth are counted from the last tooth on the right upper side of the mouth. They are then counted around the top jaw until the last tooth on the upper left which is letter J. The last tooth on the bottom right is K and the last tooth on the bottom left is T.
The permanent teeth are simply counted using numbers beginning at the right maxillary third molar or last tooth in the upper jaw on the right. The teeth are then counted around the top jaw until the last tooth on the upper left which is number 16. The bottom teeth are counted in the same way starting at the last tooth on the bottom right which is number 17 around the jaw to the last tooth on the bottom left which is number 32.
Palmer system
The Palmer system of notation was used prior to the FDI World Dental Federation notation and is now used mostly in the United Kingdom. This system of notation uses the numbers 1 through 8 for adult teeth and the letter A to E for the deciduous teeth. It also uses specific symbols to show which quadrant of the mouth the tooth is located. The letter or number combined with the symbol would show which tooth was begin identified. This system was superseded by the FDI World Dental Federation notation because it is difficult to replicate the symbols on a computer keyboard.
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